Apparatus for removing inductive effects from electric lines



(No Model.) 2 Sheets-Sheet 1.

E. THOMSON. APPARATUS FOR REMOVING INDUOTIVB EFFECTS FROM ELECTRIC LINES.

Patented June 30,1891.

(No Model.) 2 Sheets-Sheet 2.

E. THOMSON. APPARATUS FOR REMOVING INDUGTIVE EFFECTS FROM ELECTRIC LINES.

No. 454,890. Patented June 30,1891.

UNITED STATES PATENT ()FEICE.

ELIHU THOMSON, OF LY NN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON- HOUSTON ELECTRIC FOMPANY, OF CONNECTICFT.

APPARATUS FOR REMOVING INDUCTIVE EFFECTS FROM ELECTRIC LINES.

SPECIFICATION forming part of Letters Patent No. 454,890, dated June 30, 1891.

Application filed April 8, 1889. Serial No. 306,386- (No model.)

T ZZZ 77107 74 t m y O LOWIL: trio-light circuit or inducing-circuit, as it is Beit known that I, ELIHU THOMSON, a citisufficient to have the electric-light circuit act zen of the United States, and a resident of upon an induction apparatus as a primary 55 Lynn, in the county of Essex and State of whose secondary is connected as a primary 5 llfassachusettahave invented a certain new for another induction-coil whose secondary and useful Apparatus for Removing Inducin turn is in the telephonic circuit. Curtion Effects from Electric Lines, of which the rents of secondary, tertiary, or other inducfollowing is a specification. tion may therefore be employed, provided 60 My invention relates to that class of devices that the reflection, as it were, of the impulses to by which harmful effects of induction on any of one circuit into the other is not attended electric line produced by another may in a by an irregular displacement of phase or lag large measure be removed and nearly obor correspondence in time of the impulses, so viated. It is especially applicable to removthat they cannot bebrought intoharmony for 6 5 ing the effect on telephonic systems of incounteracting each other.

I 5 duction from electric-lighting lines running The general objectof my invention is to obparallel thereto over considerable spaces, tain a compensation for the induction from which induction may rise to an amount makone line to several others in a simple and ing the use of the telephonic lines difficult effective manner without in so doing causing 70 and troublesome. one of the affected lines to induce currents My present invention is designed as an imupon another affected line or lines. Thus in provement on that method of compensating the case of two telephone-circuits affected by for the induction of one line'upon another an electric-light wire my invention permits in which the removal of the inductive effects the induction of the electric-light wire upon 7 5 of one circuit or line upon another is atboth telephone-wires to be eliminated withtained by establishing in another portion of out causing induction from one telephone circuit, taking the form of a coil, a counterwire to another. induction equal to the induction of the lines Myinvention consists, essentially,in setting themselves one on the other. To carry out this up a counteracting field of induction, which 80 plan it is only necessary to insert into the line operates upon both telephone-circuits, each 0 receiving the harmful induction a coil which of which latter is arranged in a different poris magnetically related or inductionally retion of the field of counter-induction, but in lated to another coil in the line itself proposition not to induce upon the other.

ducing the trouble to adjust the angular po- My invention consists, also, in certain other 8 sitions of the two coils with respect to each improvements, to be first described, and then 3 5 other, or their distance apart, or both, or the specifically stated in the claims.

amountofironwhichisinclosedbythem,orby In the accompanying drawings, Figure 1 both of them, or the portion of the magnetic illustrates a simple case of induction between circuit which traverses one of them, or both of a telephone-line audau electric-light line com- 0 them, until the desired amount of counter or pensated by a counter-induction adjustable 4o inverse induct-ion takes place, which balances in accordance with one part of my invention. the induction originally found. It is neces- Figs. 2, 3, a, and 5 illustrate ways of varying sary, of course, that the connections be so the counter-induction. Figs. 6,7, 8, and.) are made that an impulse inductively set up diagrams illustrating my present invention. 9 5 shall be met bya reverse or opposite impulse In Fig. 1 the line T T T represents an ordialso inductively set up. One of these imnary telephone-line, which lies parallel to a pulses, however, is that which is due to the line L L L either along a part or the whole of long lines in parallelism on poles or in 0011- its course. The line in the electric-lighting duits, and the other is that due to the ad justcircuit is one in which fluctuations or alterna- IOO ment of the inducing-coils one to the other. tions occur in the current supplied from a It is not essential that the coil in the telegenerator or source D. In the telephone-line phonic or other circuit be directly related iuare the ordinary instruments of any pattern. ductively to the balancingcoil in the elec- Under the circumstances the electric-light line will influence the telephone-line inductively, and if the lengths of wire which are parallel. are sufficient may give rise to some trouble in the use of the telephonic instru ments. Looped into the electric-light line at any convenient point is the coil P, of moderate dimensions or comparatively small num ber of turns, according to the strength of the current and the induction which it is expected to balance. Placed near it, either parallel to it or at an angle with its axis, is a coil S, generally of much finer wire, and including with it the telephone-circuit T as a loop. By adjusting the relative angular positions of the coils S and P with respect to each other while listening at a telephone in the telephone-line a counter-induction may be set up equal to that which is produced on the main line, thus producing silence in the telephonic circuit.

Fig. 2 shows a simple arrangement for adjustment of the coil P as mounted in a vertical plane on a base, while the coil S is mounted on an axis which permits it to he turned at any angle with the plane of P, and a slotted slide at G permits its approach and recession, as needed, from the coil P. The coil S may in fact be arranged to be inverted, so as to insure the correct direction of itsimpulses. The adjustment so provided makes it easy to balance inductions found to exist, provided the coils P and S are of sufficient size or magnetizing-power relatively. Very small coils are, however, capable of overcoming the induction, and may be made smaller still if one or both of them are provided with an iron core.

Fig. 3 shows the coil P provided with an adjustable iron core I or an iron-wire bundle, which can be moved through the axis of the coil P toward and from the coil S, thereby modifying the inductive effects as may be needed.

I11 Fig. at the coil P, with its core I, is placed opposite a sectional coil S, whose sections are differently related as to distance from P, as shown, with a device or sliding contact K for including different portions of the wire S in the telephonic circuit to which it is connected. It is not necessary, however, that the inductionbe direct, providing the relation of phases of induction are not greatly disturbed. Thus in Fig. 5 L L may be a parallel electric-light line and the line T T a telephone-line. In the circuit L L is a coil P, wound upon a ringcore I. On the'same core a secondary coil S is also wound, and therefore takes up inductively the waves or impulses transmitted to it by induction from the coil P in the electriclight line. The coil S is, however, connected with the coil P on another core 1 on which again is placed a secondary S inserted into the telephone-line. A variable resistance V may be introduced into the circuit of S and P for modifying the inductional strength of the current. In this case it is evident that the coils in the lighting and telephone lines P and S respectively, may be at considerable distances apart, while the balaneing-induc tion. is transmitted in a neutral and separate circuit.

Having described some of the ways of adjusting and supplying counter-induction, I will proceed to describe some of the ways of carrying out my present invention.

In Fig. 6, T T and T T indicate two lines parallel with or adjacent to varying extents or varying distances to the electric-light line L L, with alternating or fluctuating currents flowing thereon. The coil P in the electriclight line has on one side of it adjustably placed a coil S in the circuit of the line T T, and in the other side a similar coil S in the circuit of line T, whereby the coil P may inductively act on both circuits T T and T T. The coils S S are kept sufficiently far apart as not to allow cross-talk by induction from one of the telephone-coils to the other.

Fig. 7 illustrates a modified wayof permitting a single coil P of moderate size in an electric-light line to affectinductively a number of coils variably placed as to the power of induction and each inserted in a particular telephone-circuit without permitting the approach of the small telephonic-circuit coils to allow cross-induction or cross-talk. The small coils are adjusted both as to the position and angle, &c., and arranged around the coil P, which may be without a core of any kind, or which may have a core I, of iron-wire bundles, threaded through it and run in different directions, as indicated, to separatelyinfluenced coils S, &c., which coils are connected in individual telephone-circuits.

In Fig. 8 the coil P is of rather large dimensions and each of the small telephonic coils S i", &c., is wound upon an iron core and placed at a proper position in the air-field de veloped by the coil P to receive the balancing or counter induction required to remove the active induction of the telephone-lines to which it is connected.

Fig. 9 indicates how, when several lines are inductively related and induction occurs from one to the other, they may be made to balance their inductive effects. I have shown here two electric-light lines L L and L L acting inductively in varying degrees on three telephone-lines T T, and T T, and T T the lines being at different distances apart and different distances one from the other, and receiving, therefore, different degrees of inductive effect. In the circuit of the lighting-line L L is placed the coil P, and also the coil P in the circuit L L, which is so made, however, that the line L L is the stronger in its inductive effect upon the coils S, &c., it (L') being nearer to the telephone lines. It is therefore given a position on the common core I nearer to the compensating-coils for the telephone-circuits S S S. The line T, being close to the electric-light lines, receives the most powerful induction, and its coil S is therefore in the strongest field of the core I. The coil S is in the air ive relation to one another.

cuit to the line T T and receives the next Weaker induction, and the coil S is in the circuit of line T T which is farthest away from the electric-light lines and receives the weakest inductive effect. The coil is placed at an inefficient inductive relation with the core I. Many other modifications in the lay-out of the devices or the plans of their positions and proportions maybe made by those skilled in the art.

It will be observed in the case of Fig. 0 that the two or more electric-light lines act to give a composite field of induction, into which are independently inserted, withoutinductive relation to each other, telephone-coils or antiinduction generators. The absence of appreciable cross-induction in the counter-induction apparatus which is secured in the arrangement, Fig. 0, is also obviously secured in the arrangements shown in Figs. '7 and 8, since in the-latter cases likewise the coils in the several telephone-lines are established at different parts of the field and out of induct- The use of the air-field, as described, also conduces to freedom from cross-talk from one telephone-line to the other through the compensating devices.

lVhat I claim as my invention is- 1. In an apparatus for compensating for induced currents upon two or more circuits from another, the combination, substantially as described, of a reactionary magnetic field produced by the inducing-circuit, and compensating coils for the induced circuits placed in different parts of said field, but out of in ductive relation to one another.

2. The combination, substantially as described, with two or more inducing electric lines and two or more electric lines inductively affected thereby, of a compound compensating air-field produced by the currents of the two inducing-circuits, and counter-inducing coils or indnotion-generators for the several affected lines placed out of inductive relation to one another, each in a composite air-fi eld produced by the said inducing lines or circuits.

The combination, substantially as described, of two or more inducing electric lines and .two or more telephone-circuits inductively affected thereby and each provided with a counter-inducing coil or inductiongenerator placed in a composite air-field produced by the two inducing-lines, each counter-inducin g coil or generator for a telephoneline being located in position to be out of i11- ductive relation to the coil or generator for other telephone-line.

Signed at Lynn, in the county of Essex and State of Massachusetts, this 1st day of April, A. D. 188.).

ELIHU THOMSON.

Witnesses:

- J. W. GIBBoNEY, .T. R. JoHNsoN. 

